Geography - Rocks and Fossils Flashcards
What are all rocks made up of?
Minerals
What are the three different families of rocks?
Sedimentary
Igneous
Metamorphic
Where do geodes form?
Inside magma
What do we call two types of molten rock?
Lava (above surface)
Magma (below surface)
What does water leave behind when it evaporates?
Minerals
Why do some geodes have different colour crystals?
Different types of minerals changes the colour
What causes there to be a “gap” in the molten rock?
When gas gets trapped in the rock it leaves pockets.
How many rocks can you name?
Granite
Obsidian
Limestone
Slate
Sandstone
Quartz
Marble
Flint
Chalk
Mudstone
Gneiss
Shale
What are rocks made up of?
A mixture of minerals and non-living creatures
Igneous rocks are formed in two ways, resulting in two types of igneous rock. What are they?
Intrusive (inside)
Extrusive (outside)
Draw and label a diagram showing an intrusive igneous rock formation.
Describe how intrusive igneous rocks form.
Inside the Earth’s Crust.
Large crystals form
Minerals have time to bond
Formed in magma.
Cools slowly
eg Granite.
An example of an intrusive igneous rock is…..
…. granite or gabbro
Describe how extrusive igneous rocks form.
Outside the Earth’s Crust
Small crystals form
Minerals do not have time to bond
Formed in lava
Cools quickly.
eg. basalt
An example of an extrusive igneous rock is…..
…basalt, obsidian, lava bomb
Draw and label a diagram showing an extrusive igneous rock formation.
Describe the formation of igneous rocks.
Key marks in a mark scheme
What does weathering mean?
Weathering erodes rocks at the surface to create smaller rocks (sediments).
The breaking down of rock due to atmospheric conditions (wind/rain/ice/sun etc)
What does transportation mean?
Creates sediments and rocks that are being moved by moving ice or wind.
What does deposition mean?
When rocks have stopped moving into the sea, river or desert and get deposited.
What does strata mean?
The layers that form in a sedimentary rock
What does lithification mean?
The process of turning into a sedimentary rock.
Create a diagram showing the formation of sedimentary rocks.
What happens during cementation?
The moisture squeezes out and the sediments stick together to create a sedimentary rock.
What is compaction?
It is when the bottom layers are squeezed together from the weight of the layers above and become compacted.
What is erosion?
The process of rocks being broken down.
Key information about intrusive rocks
Inside the Earth’s crust
Magma
Large crystals
Minerals have time to bond
Cooled slowly
eg. Granite
Key information about extrusive rocks
Outside the Earth’s Crust
Lava
Small crystals
Minerals don’t have time to bond
Cooled quickly
eg. Basalt
What does the word morph mean?
It’s when something changes form.
How are metamorphic rocks formed?
They are formed deep within the Earth where there is lots of heat from the magma below and lots of pressure from the rocks above.
What does the “parent rock” sandstone become when heat and pressure is applied to become a metamorphic rock?
Quartzite
What does the “parent rock” granite become when heat and pressure is applied to become a metamorphic rock?
Gneiss
What does the “parent rock” limestone become when heat and pressure is applied to become a metamorphic rock?
Marble
What does the “parent rock” shale or clay become when heat and pressure is applied to become a metamorphic rock?
Slate (low grade)
More pressure and heat
Phyllite
More pressure and heat
Schist
More pressure and heat
Gneiss (high grade)
What are metamorphic rocks?
They are rocks that have changed due to heat and pressure.
Examples of sedimentary rocks and uses
Limestone - making cement
Coal - fires
Chalk - writing
Sandstone - building material
Examples and uses of igneous rocks
Pumice - bath scrub
Granite - kerb stones
Examples of metamorphic rocks
Slate - roofing
Marble - making statues
Which rock is made up of layers that have been squashed together?
Sedimentary
Which rock is formed when lava or magma cools down and crystallises?
Igneous
Which rock is formed under intense heatand pressure causing it to change?
Metamorphic
How are igneous rocks formed?
Inside or outside the Earth’s Crust. They are formed by the cooling down of magma and lava.
What has happened to metamorphic rocks to make them the way they are?
Heat and pressure
Name a use for sedimentary rock
Creates fire or writing
Name as use for metamorphic rocks
Roofs and statues
Name a use for igneous rocks
Bath scrub
Give an example of a sedimentary rock
Coal, sandstone, puddingstone
Give an example of a metamorphic rock
Slate
Give an example of an igneous intrusive rock
Granite
Give an example of an igneous extrusive rock
Basalt, pumice, lava bomb, obsidian
What are sedimentary rocks formed from?
Sediments that have been compacted together.
What do we call the process of turning into a sedimentary rock?
Lithification
What name do we give the layers that form in a sedimentary rock?
Strata
Name two processes that cause rocks to be broken down into smaller pieces.
Weathering and sedimentation
What processes change a sedimentary rock to a metamorphic?
Heat and pressure
What processes change a metamorphic rock to an igneous?
Melting and cooling
What processes change an igneous rock to a sedimentary?
Sedimentation, compaction, weathering, erosion (lithification)
Why do we almost only find fossils in a sedimentary rock?
We can’t find fossils in igneous rocks as they would have melted. We find a few in metamorphic because they’ve experienced heat and pressure.
What is a fossil?
Remains of prehistoric plants and animals.
How do we know about animals that have died millions of years ago?
Fossils
What can we learn from a trace fossil?
How the animal lived and cared for its young.
How is a mold fossil created?
Mud around a dead animal hardens and creates a mold of the shape/imprint.
How is a resin fossil created?
When an insect gets stuck in the sap in the tree. The sap hardens and turns into amber which preserves the body.
Why is a body fossil rare?
A dinosaur needs to die near water and its skeleton cannot be scattered around.
How is a body fossil formed?
An animal dies.
Some body parts decay - usually only the skeleton is left.
The skeleton is covered in sand, earth, rock, seabed before the bones can disappear.
Minerals slowly fill the space in layers - in the exact shape of the bones.
Under lots of pressure, new minerals harden into rock.
Over a very long time, the bones break down and leave space, like an empty mould.
The earth is eroded away by the weather/sea. The fossil rock is exposed and discovered.
Which type of igneous rock forms from cooling magma?
Intrusive
Which type of igneous rock forms from cooling lava?
Extrusive
Which type of igneous rock has small crystals?
Extrusive
Which type of igneous rock has more time for minerals to bond?
Intrusive
Draw and label the rock cycle
What is the name of the process given to the constant creation and recycling of rocks on the Earth?
The Rock Cycle
Where does Intrusive Igneous rock form?
Deep underground
Where does Extrusive Igneous rock form?
On the Earth’s surface
Describe how a resin fossil is created?
The tree sap traps an insect, it hardens and turns to amber, preserving the inset.
Where do Metamorphic rocks form?
Deep underground
What two conditions are needed to form a Metamorphic rock?
Heat and Pressure
Igneous rocks that are known as Extrusive can also be know as what?
Volcanic
What is the difference between Lava and Magma?
Magma is molten rock below the Earth’s surface, Lava is molten rock above the Earth’s surface
When an Igneous rock cools we say it CRYSTALISES. What does this mean?
Different minerals within the rock band together as the rock cools down, these minerals form different coloured crystals on the rock. They can be large or small. We call this crystalizing.
Why do some Igneous rocks have small crystals?
The cooled down quickly, usually on the Earth’s surface. This means there was little time for the minerals to bond together, As a result they are only small crystals.
Why do some Igneous rocks have large crystals?
The cooled down slowly, usually under the Earth’s surface. This means there was lots of time for the minerals to bond together and as a result they have grown large crystals.
What are Clastic Sedimentary rocks fromed from?
Fragments of other rocks that have been bonded together.
What do we call the process of turning into a Sedimentary rock?
Lithification
What name do we give to the layers that form in Sedimentary rock?
Strata
Where do sediments usually end up before being turned into a Sedimentary rock?
Seas/Oceans/Lakes
What do we call it when different sediments begin to get stuck together?
Cementation
What has to happen to another rock for it to turn into a metamorphic rock?
Heat and Pressure
What does the word ‘morph’ mean?
To change
During compaction, what is squeezed out?
Moisture
The process of turning into a sedimentary rock, is called?
Lithification
Give an example of a Clastic Sedimentary rock
Sandstone / Shale / Gritstone / Puddingstone (Conglomerate) / Limestone / Mudstone / Siltstone
List the 4/5 theories that caused dinosaur extinction.
Climate change, volcanoic eruption, diseases and meteorite, competition
The type of metamorphic rock formed depends on the original rock that it was made from e.g. Granite turns into ………………………………
Gneiss
How do sediments turn into a sedimentary rock (in two words)?
Compaction and Cementation (Lithification)
How does an igneous rock turn into magma (in one word)?
Melting
How does a Sedimentary rock turn into a Metamorphic rock (in two words)?
Heat and Pressure
How does a Sedimentary rock turn into a Igneous rock (in one word)?
Melting
How does a Metamorphic rock turn into sediments?
Weathering and Erosion
Name a use for Granite
Kitchen Surfaces / Kerb stones/ building material
Name a property of sandstone that makes it useful for building?
It can be easily carved and shaped into blocks
Why do we use Slate for roofing?
It is water resistant and can be cut into flat tiles
Name a use for Coal
It burns, used for fires and energy production.
Name a use for Pumice
Bath scrub
Name a use for Obsidian
Tools for cutting. It is also often used to make jewellery.
Which rock are we most likely to find fossils?
Sedimentary
What are the four types of fossil?
Body / Mold / Resin / Trace
What are the four types of trace fossil?
Bite marks / Footprints / nest / Droppings
How long ago did Dinosaurs go extinct?
65 million years ago
What does the word Dinosaur mean?
Terrible Lizard
Which animals are relatives of Dinosaurs?
Turtles / Crocodiles / Birds
What was the first time period of the Dinosaurs?
Triassic
What was the second time period of the Dinosaurs?
Jurassic
What was the last time period of the Dinosaurs?
Cretaceous
What name do we give to the era that included the Triassic, Jurassic, Cretaceous?
Mesezoic Era
How does a mold fossil form?
A mold fossil is the imprint left by an organisms shell or skeleton on another rock.
How does a resin Fossil form?
Animals (usually insects) are trapped in tree sap (resin). Over time this tree sap becomes hardened, turning into amber, still containing the insect, preserved inside.
Why are complete body fossils so rare?
When an animal does it is often broken appart by scavagers and its remains are scattered. Whole body fossils require the organism to have died and been buried quickly. This usally happens in water.
What can we learn from trace fossils?
Facts about an animals life. Primerily Diet and hunting patterns.
The type of metamorphic rock formed depends on the original rock that it was made from e.g. Coal turns into ………………………………
Diamond
The type of metamorphic rock formed depends on the original rock that it was made from e.g. Shale turns into ………………………………
Slate / Schist / Gneiss
The type of metamorphic rock formed depends on the original rock that it was made from e.g. Sandstone turns into ………………………………
Quartzite
The type of metamorphic rock formed depends on the original rock that it was made from e.g. Chalk/Limestone turns into ………………………………
Marble
What does the word extinction mean?
Died out
